The long term goal ofthis research is to develop effective and sustainable means to prevent tobacco and other substance use among Latino youth through community-based family-skills training. Though family-skills training has proven to be an effective means to prevent substance use in adolescents, few interventions have specifically targeted Latino families. Furthermore, few of these have been developed using a community based participatory research process that may increase the local relevance, appropriateness, and likelihood of sustainability of such a project. Over the last two years our partnership has engaged immigrant Latino families in a feasibility study of a evidence-informed parenting curriculum designed and conducted in collaboration with Latino families and Latino-servitig community agencies. The primary aim of the current proposed project is to evaluate the effectiveness ofthis eight session family-skills intervention directed at immigrant Latino families of middle school aged youth as delivered in partnership with eight community organizations. This study is a randomized controlled trial with a delayed treatment condition for the control group. Randomization will occur at the level ofthe family within the agencies. Specific aims are first to determine the effectiveness of this familybased intervention to reduce tobacco and other substance use intention and decrease the growth trajectory of tobacco intention in middle school aged (10-14) Latino youth utilizing a community-based randomized controlled trial. Our Secondary Aim is to assess the effect ofthe intervention on the Latino parent-youth relationship and parenting practices. Finally, our third and exploratory aim is to assess CBPR partnership, operational, and contextual factors that contribute to the successful implementation ofthe intervention at the eight community sites participating in the collaborative project. This study is innovative in a number of ways: 1) it addresses tobacco and other substance use prevention for a large and growing immigrant population in the United States;2) we expect the proposed study to provide a model for collaborative design, implementation, and evaluation of substance use prevention interventions with diverse community agencies.